package com.ja.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

/**     
 * 项目名称：cp   
 * 类名称：CodeUtil   
 * 类描述：   验证码类
 * 创建人：Administrator   
 * 创建时间：2018年10月10日 上午9:35:11   
 * @version        
 */
public class CodeUtil {

	public static int createdCode(HttpServletRequest request, HttpServletResponse response) throws Exception {
		HttpSession session = request.getSession();
		response.setContentType("image/jpeg");
		int width = 60;
		int height = 20;

		// 设置浏览器不要缓存此图片
		response.setHeader("Pragma", "No-cache");
		response.setHeader("Cache-Control", "no-cache");
		response.setDateHeader("Expires", 0);

		// 创建内存图像并获得图形上下文
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		Graphics g = image.getGraphics();

		// 产生随机验证码 定义验证码的字符表
		String chars = "23456789";
		char[] rands = new char[4];
		for (int i = 0; i < 4; i++) {
			int rand = (int) (Math.random() * 8);  
			rands[i] = chars.charAt(rand);
		}
		//产生图像 画背景
		g.setColor(new Color(0xDCDCDC));
		g.fillRect(0, 0, width, height);

		//随机产生120个干扰点
		for (int i = 0; i < 120; i++) {
			int x = (int) (Math.random() * width);
			int y = (int) (Math.random() * height);
			int red = (int) (Math.random() * 255);
			int green = (int) (Math.random() * 255);
			int blue = (int) (Math.random() * 255);
			g.setColor(new Color(red, green, blue));
			g.drawOval(x, y, 1, 0);
		}
		g.setColor(Color.BLACK);
		g.setFont(new Font(null, Font.ITALIC | Font.BOLD, 18));

		// 在不同高度输出验证码的不同字符
		g.drawString("" + rands[0], 1, 17);
		g.drawString("" + rands[1], 16, 15);
		g.drawString("" + rands[2], 31, 18);
		g.drawString("" + rands[3], 46, 16);
		g.dispose();

		// 将图像传到客户端
		ServletOutputStream sos = response.getOutputStream();
		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		ImageIO.write(image, "JPEG", baos);
		byte[] buffer = baos.toByteArray();
		response.setContentLength(buffer.length);
		sos.write(buffer);
		baos.close();
		sos.close();
		session.setAttribute("code", new String(rands));
		return 1;
	}
	
	
}
